The daily variability of bronchial responsiveness to methacholine.
Ten mild atopic asthmatics on inhaled beta 2-agonists alone were studied in order to determine the repeatability of methacholine inhalation provocation tests at 24 h intervals over a period of 5 days. Such patients are most frequently studied in therapeutic trials of anti-asthmatic medications. There were no significant differences in results obtained on any of the days and no evidence for the development of tolerance to methacholine in this group of patients at one day intervals. The 95% confidence interval for repeatability of the results was +/- 1.05 doubling doses of methacholine, and 95% range +/- 2.36 doubling doses, comparable to the results obtained by other investigators on similar patients. Some investigators have produced more highly repeatable results but these have generally been obtained using highly selected groups of patients.
Trigg
C J
CJ
Academic Dept of Respiratory Medicine, St Bartholomew's Hospital, London, UK.
Jhalli
N
N
Herdman
M J
MJ
Cundell
D R
DR
Thomas
J M
JM
Davies
R J
RJ
D000293:Adolescent; D000328:Adult; D000403:Airway Resistance / Q000187:drug effects; D000704:Analysis of Variance; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D001985:Bronchial Provocation Tests / Q000379:methods / Q000706:statistics & numerical data; D016084:Bronchoconstriction / Q000187:drug effects*; D002985:Clinical Protocols / Q000592:standards; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D015203:Reproducibility of Results; D013997:Time Factors
D016210:Methacholine Chloride